The microscopic functional unit of the kidney that filters blood and forms urine is the nephron.
Missing Word
nephron
Each kidney contains a very large number of nephrons, each made of a renal corpuscle and a tubule that reabsorbs and secretes substances before the urine reaches a collecting duct.
Category: Nephron and Filtration
Question 2
Proximal tubule cells can make new glucose from noncarbohydrate sources, a process called gluconeogenesis that speeds up during acidosis and stress.
Missing Word
gluconeogenesis
Gluconeogenesis is the synthesis of glucose from sources such as amino acids and lactate; the liver is the main site, and the kidneys add to it, with output rising under cortisol and acidosis.
Category: Renal Regulation
Question 3
The tuft of fenestrated capillaries enclosed by Bowman's capsule is the glomerulus.
Missing Word
glomerulus
The glomerulus is the capillary bed where blood pressure pushes water and small solutes out into the capsule, the first step in forming urine.
Category: Nephron and Filtration
Question 4
The kidney process that is the reverse of reabsorption, tubular secretion, moves substances such as hydrogen ions, potassium, creatinine and many drugs from the peritubular blood into the tubule lumen.
Missing Word
secretion
Secretion is the opposite direction from reabsorption: it adds substances to the tubular fluid so they leave the body in urine, which is a major route of drug elimination.
Category: Nephron and Filtration
Question 5
The cone-shaped renal pyramids are found in the inner region of the kidney called the medulla.
Missing Word
medulla
The renal medulla lies inside the cortex and holds the pyramids, which contain loops of Henle and collecting ducts that drain urine toward the calyces.
Category: Kidney Structure
Question 6
The kidney's ability to hold GFR fairly constant across a wide range of blood pressures, through the myogenic response and tubuloglomerular feedback, is called autoregulation.
Missing Word
autoregulation
Autoregulation is intrinsic to the kidney and protects filtration from everyday swings in blood pressure; it fails when pressure drops very low, as in shock.
Category: Renal Regulation
Question 7
Fluid volume excess, an abnormal increase in the volume of circulating blood, is also called hypervolemia.
Missing Word
hypervolemia
Hypervolemia results from too much fluid intake or too little output, and in kidney disease it shows up as edema, crackles, neck vein distention and rapid weight gain.
Category: Fluid Volume Excess
Question 8
An abnormal buildup of fluid in the peritoneal cavity, which enlarges the abdomen in cirrhosis or kidney disease, is called ascites.
Missing Word
ascites
Ascites is one of the signs of fluid volume excess, along with dependent edema and crackles, and it can make breathing difficult when large.
Category: Fluid Volume Excess
Question 9
The paired muscular tubes that carry urine from each renal pelvis down to the bladder are the ureters.
Missing Word
ureters
Peristaltic waves in the ureters push urine toward the bladder, and stones lodged in a ureter cause the severe pain known as renal colic.
Category: Lower Urinary Tract
Question 10
The smooth, triangular area of the bladder floor marked by the two ureteral openings and the urethral opening is the trigone.
Missing Word
trigone
The trigone does not stretch as the bladder fills, and the ureters pass obliquely through the wall near it, which helps prevent urine from flowing back toward the kidneys.
Category: Lower Urinary Tract
Question 11
The layer of smooth muscle in the bladder wall that contracts under parasympathetic stimulation to push urine out is the detrusor.
Missing Word
detrusor
The detrusor muscle empties the bladder during voiding, and overactivity of this muscle is the cause of urge incontinence.
Category: Lower Urinary Tract
Question 12
Voluntary control of the external urethral sphincter is supplied by the pudendal nerves.
Missing Word
pudendal
The pudendal nerves are somatic nerves, so they let a person consciously hold or release urine, unlike the autonomic nerves that control the bladder wall and internal sphincter.
Category: Lower Urinary Tract
Question 13
Swelling of the renal pelvis and calyces caused by urine that cannot drain past a blockage, such as a stone lodged in a ureter, is called hydronephrosis.
Missing Word
hydronephrosis
Hydronephrosis develops when an obstruction such as a stone, a tumor or an enlarged prostate backs urine up into the kidney; the rising pressure lowers filtration and, if not relieved, damages kidney tissue.
Category: Renal Disorders
Question 14
When blood pressure in the afferent arteriole falls, the juxtaglomerular cells release the enzyme renin.
Missing Word
renin
Renin starts the renin-angiotensin-aldosterone cascade, which constricts blood vessels and promotes sodium and water retention, so blood pressure and kidney perfusion are restored.
Category: Renal Regulation
Question 15
A procedure that uses focused shock waves to break a large kidney stone into fragments small enough to pass is lithotripsy.
Missing Word
lithotripsy
Lithotripsy is used when a stone is too large to pass on its own; afterward, patients are taught to drink plenty of fluid and may be asked to strain the urine to collect fragments.
Category: Renal Disorders